1. Field of the Invention
This invention relates to an anthropomorphic robot arm used to carry out various types of work normally carried out manually by humans, and particularly to an anthropomorphic robot arm which can be used as the end factor for robots, prosthetic arms or other types of manipulators.
2. Prior Art Statement
The degrees of freedom of the human arm are centered in the wrist and hand, enabling it to execute complex and agile movements. But with a robot arm intended to simulate the human arm, placing actuators in these same locations to achieve the same degrees of freedom and similarly move corresponding joints typically results in these parts becoming extremely heavy, making the robot arm extremely large and unwieldy, unable to withstand the rigors of realistic use.
Nevertheless, when contemplating a robot arm to be used as a substitute for a human arm, it is preferable that it have degrees of freedom similar to those of the human hand and wrist which are able to carry out a great diversity of tasks. It should also appear as similar to the real thing as possible and be easily to control.
Specifically, by providing slave units which comprise the robot arm at positions corresponding to the human hand and wrist, arranging the slave units in the form of a human hand and arm, and enclosing the structural elements inside these slave units to give an external appearance similar to the human hand and arm, a one-to-one correspondence can be achieved with a master device mounted on a human arm to send command signals to operate the fingers and the like, resulting in control becoming extremely simple.
However, although grasping mechanisms of various structures have been proposed in the past, any robot arm which has on its hand five fingers which function similarly to human fingers, and is similar to the human arm even in the shape of the upper arm has been, as described above, of such complex structure and extremely large size as to be unwieldy impractical, so we are as yet not aware of a practical proposal.
The object of this invention is to provide a robot arm of a structure which is functionally as similar as possible to the human hand and arm, and particularly has on its hand five fingers which function similarly to human fingers, and is similar to the human arm even in the shape of the upper arm.